Durable rfid tag

ABSTRACT

Plastic asset identification tags are described. The tags define an attachment feature by which the tag is attached to the asset. The tag also defines a cavity or slot in which an RFID transceiver is placed. Epoxy fills the remainder of the slot or cavity. The RFID transceiver is programmed to respond to interrogation by transmitting a unique identifier that is associated with the object to which the tag is attached. Additional information about the object may also be responsively transmitted, and in some embodiments that additional information is also written on the outside of the tag. Other tags seal the RFID transceiver within a pocket of flexible fabric-supported PVC.

REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.61/080,821, filed on Jul. 15, 2008 and International Application No.PCT/US2009/037150 filed on Mar. 13, 2009. The entireties of theseapplications are hereby incorporated by reference.

FIELD

Some embodiments disclosed herein relate to an identification tag. Morespecifically, some embodiments relate to a tag bearing data retrievableby radio frequency stimulation.

BACKGROUND

The United States Occupation Safety and Health Administration (OSHA)requires chains and certain heavy equipment used in industrial settingsto carry an identifying tag. The tag is stamped or engraved withidentifying information, such as a serial number, model number, andother characteristics. Standard descriptive and/or warning text isengraved, molded, or embossed in the tag. Such tags are often made ofsteel or other durable metal.

Unfortunately, these industrial identification tags often deform in theface of typical industrial use. For example, when a chain is draggedbehind a vehicle over the road, run over, or struck against a metalstructure, or even where it might be subjected to intentional stresssuch as shot peening, the tags on these chains are often deformed beyondrecognition (certainly beyond accurate, useful reading of data on itssurface). Then, in order to comply with regulations, the tag must bereplaced before the chain or equipment is used again.

There is a need, therefore, for more durable tags from which thenecessary information can be read even after exposure to sometimesextreme stresses in industrial environments.

In addition, maintenance and use of industrial tags requires regularchecking for the presence and proper condition of the tags. There is,therefore, also a need for convenient methods for checking industrialtags for function and legibility.

SUMMARY

It is, therefore, an object of some forms of the invention to provide amore durable identification tag.

It is also an object of some forms of the invention to provide a tag forchains and heavy equipment in industrial settings, where the tag carriesinformation that is readable without physically contacting the tag evenafter the tag is subjected to high stresses of industrial use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an identification tag according to afirst embodiment.

FIG. 2 is a plan view of the embodiment of FIG. 1.

FIG. 3 is a perspective view of an identification tag according to asecond embodiment.

FIG. 4 is a perspective view of an identification tag according to athird embodiment.

FIG. 5 is a plan view of an identification tag according to a fourthembodiment.

FIG. 6 is a perspective view of an identification tag according to thefourth embodiment as it is being affixed to an industrial liftingdevice.

FIG. 7 is a schematic view of a test configuration applied to anidentification tag according to the fourth embodiment.

DESCRIPTION

For the purpose of promoting an understanding of the principles of theinvention, reference will now be made to certain embodiments illustratedin the disclosure, and specific language will be used to describe thesame. It will nevertheless be understood that no limitation of the scopeof the invention is thereby intended, such alterations and furthermodifications in the illustrated device and such further applications ofthe principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates.

Generally, one form of the present invention is a durable identificationtag made of a flexible plastic material, and in which an RFIDtransceiver is embedded. The tag is applied to a chain, heavy equipment,or other uniquely identified object. Another form is a thin, flexibletag that includes a sealed pocket holding an RFID transceiver. This tagis sewn onto a sling, rope, or other device to facilitate management ofthat asset and data about that asset.

Turning now to the embodiment illustrated in FIG. 1, tag 100 includes aninformation-bearing surface 102, through-hole 104, RFID transponder 106,and transponder embedding cavity 108. Information-bearing region 102 isengraved with information about the item to which tag 100 is attached.In the illustrated embodiment, that object is a chain, and the displayedinformation includes the working load limit (WLL), serial number, size,grade, reach in feet and inches, and number of legs of the chain. Insome applications, additional information about the chain, such asacquisition date and source, maintenance records, and the like, ismaintained in separated paper and/or electronic records. In otherembodiments, such additional information is encoded on the RFIDtransponder 106 instead of or in addition to the information engraved ininformation-bearing surface 102.

RFID transponder 106 is positioned in transponder embedding cavity 108as will be discussed further below. In the exemplary embodiment, theRFID transponder 106 is an INFOCHIP RFID chip manufactured anddistributed by InfoChip Systems, Inc., of Wetaskiwin, Alberta, Canada.In other embodiments, alternative RFID transponders are used. Forexample, RFID transponder 106 in various embodiments is active,semi-passive, or passive. Various transponders will have an integratedantenna, an external antenna, or both. The data provided by the RFIDtransponder 106 in various embodiments is loaded into the transponder106 before it is placed within tag 100, after it is inserted intotransponder receiving cavity 108, or repeatedly over time by remotemeans as will be understood by those skilled in the art in view of thepresent disclosure.

Turning to FIG. 2, a plan view of tag 100 is presented, and will bereferred to in a description of the fabrication of tag 100. In thisexemplary fabrication method, a sheet of plastic is prepared intorectangular sheets about 5 inches long, 1.5 inches wide, and 0.25 inchthick. The overall shape varies from one embodiment to another, but thisembodiment includes rounded corners 114 and through hole 104. A laser,such as model V460-60 produced by Universal Laser Systems Inc. ofScottsdale, Arizona, takes a computer-readable graphics file as inputand generates the outer contour accordingly, including curves 114. Thelaser also produces through hole 104 and engraves the identifying andcharacteristic information into information-bearing surface 102 asillustrated in FIG. 1.

Transponder embedding cavity 108 is then created in the end of tag 100.In some embodiments, cavity 108 is created by a rotary bit, by laser, orby other methods that will occur to those skilled in the art based uponthe present disclosure. Cavity 108 may be deep enough within the volumeof tag 100 so that impact on the surface of tag 100 is unlikely todamage the RFID transponder 106.

The remaining space in transceiver cavity 108 is then filled. Abundantoptions will occur to those skilled in the art in the selection ofmaterials with which to fill that space, but one suitable example is a2-part epoxy casting resin (RESINLAB EP 965 LVLX Black), available forexample from Ellsworth Adhesives in Germantown, Wisconsin. Alternativefilling materials include LOCTITE HYSOL E-30CL, RESINLAB EP 1046 FG orRESINLAB EP 1121, or 3M SCOTCH-WELD Structural Plastic Adhesive DP-8005,all available from Ellsworth Adhesives. The epoxy is inserted intocavity 108 after transponder 106, then cures at room temperature for onehour to a semi-rigid polymer state. Various materials are selected fordifferent use cases, considering void penetration, wetting and adhesionproperties, void penetration, air release, and finish to a smooth,high-gloss surface. Other factors include resistance to water, acids,bases and most organic solvents, ensuring that the RFID transponder 106is protected from many physical threats. Of course, other fillsubstances meet other design goals and will occur to those skilled inthe art in light of the present disclosure.

In this exemplary embodiment, the body of tag 100 is fabricated fromNYLATRON GS from DSM Engineering Plastic Products in Reading,Pennsylvania. Other embodiments are injection molded from DSM's STANYLTW363, or ZYTEL ST801AW NC010 from DuPont. Those skilled in the art willfind PVC, acrylics, and other plastics suitable for variousapplications.

The tag 100 in this exemplary embodiment is UV-resistant and durablethrough high temperatures, sun exposure, water exposure, and othernatural threats to its integrity. In this embodiment, after the fillsubstance in cavity 108 is set, the chip is encoded with information. Insome embodiments, the information encoded into transponder 106 isprecisely the data engraved in information-bearing surface 102. Inothers, only the serial number is stored in transponder 106, while instill others additional recordkeeping information is stored.

A second embodiment is shown in FIG. 3. In this variation, tag 200includes information-bearing region 202 and through-holes 204.Through-holes 204 enable the attachment of tag 200 to identified objectsby mechanical looping. An RFID transponder is embedded in tag 200 inanother transponder-placement region 208, though neither an RFIDtransponder nor the transponder-placement region is shown in FIG. 3.

FIG. 4 illustrates another embodiment, suitable for situations whenlegible writing on the outside of the tag is not needed. In thisembodiment, tag 300 comprises body 302, which defines through-hole 304and cavity 306. Transceiver 308 is placed within cavity 306, and theremainder of cavity 306 is filled with epoxy 310. This embodiment can bemade very small (relative to the size of RFID transceiver 308).

FIG. 5 illustrates another embodiment, tag 400. In this embodiment, tag400 is made primarily of 18-pound, fabric-supported PVC sheets. Tailportion 402 in this embodiment merely provides a rectangular area thatis useful for attachment to an object as will be discussed further inrelation to FIG. 6, below. Head portion 404 includes a multi-layerpocket 406 in which RFID transceiver 408 is placed. After thatplacement, pocket 406 is RF-welded shut along closed path 410. Otherclosure techniques may be used in alternative embodiments, as will occurto those skilled in the art in view of the present disclosure. As shownin these embodiments, the RF-weld along path 410 makes pocket 406substantially waterproof. The data available through RFID transceiver408 in this embodiment can be any of the options described in relationto the embodiments above, or others as will occur to those skilled inthe art in view of this disclosure.

FIG. 6 illustrates one way in which tag 400 can be affixed to certainassets. In this illustration, object 420 is a part of the asset, such asa strap, rope, sling, cable, or the like. Capacity label 430 is wrappedaround object 420 and over tag 400, then is sewn along stitching line440 using durable nylon thread or the like. The stitching crosses theedge of capacity tag 430 and upper portion 402 of tag 400, therebyaffixing both identification tag 400 and capacity tag 430 to object 420.Conventional capacity tags 430 are of a dimension and quality thatallows RFID transceiver 408 to be queried from a suitable distance.

Alternative Fabrication Technique

An alternative method for fabricating tags 100, 200, and 300 involvesinjection molding techniques. This process begins with resin in pelletform and ultraviolet-resistant dye, each of which is dried usingconventional techniques to remove moisture in advance of the injectionmolding process. In some embodiments, the resin and dye are dried toabout 0.01% moisture, while in other embodiments, the threshold is setat some other value less than or equal to 0.05%. The plastic resin anddye are then blended and loaded into a hopper for screw injectionmolding. Of course, in other embodiments, other types of molding will beused as will occur to those skilled in the art in view of the presentdisclosure.

During the molding process, the dyed resin is injected into a die toform the tag body, including defining the slot, or cavity, and any textand/or symbols that are to appear on information-bearing surface 102.The injection dies in this embodiment are water-cooled, and once theplastic is injected, the dies are cooled and the tag is ejected from thedie. In other embodiments, multi-cavity dies are used to form multipletags (having the same or different shapes and/or markingssimultaneously).

The tags are then “seasoned” by exposure to greater levels of humidityuntil their moisture content reaches about 2.7%. In other embodiments,of course, other moisture content thresholds will be used, as will occurto those skilled in the art in view of this disclosure. RFID transceiverchips are then inserted into the slot that was molded into each tag, andthe remainder of the slot is filled with epoxy.

Additional information to be added to information-bearing surface 102can be written using hand stamping, vibratory etching, laser etching, orscreen printing. Other methods of writing data on the outside of the tagso that it is visible and legible will occur to those skilled in the artin view of the present disclosure.

Testing

Tags made according to the first exemplary embodiment above have beenput through a shot peening chamber 250 consecutive times, placed under aconcrete block and jerked out 15 times, then run over with a forklift 5times, and placed on a chain and dragged behind a vehicle on the highwayfor over 2 hours. The RFID transceiver in each tag still functioned asintended.

Another tag made according to the first exemplary embodiment above wasexposed to 65,000 pounds of pressure asserted perpendicular to the largeside that includes information-bearing surface 102. Though the text onthe tag was somewhat deformed, it was still legible (it was primarilyjust larger than it had been), and the RFID transceiver still worked.

As illustrated in FIG. 7, a tag 500 of the form illustrated in FIGS. 5-6was attached to an industrial-grade sling 510, and a length-wise strainforce F was imposed lengthwise on each end of the sling 510. The pointat which the tag 500 was affixed to the sling 510 was placed outside thebight 520 in the sling 510, within the protective sheath of the sling510 on the side opposite post 530. A pulling force of 2F=45,000 poundswas applied, and the RFID transceiver 540 in tag 500 still functioned.

While the inventions have been illustrated and described in detail inthe drawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatthe preferred embodiment has been shown and described and that changesand modifications that come within the spirit of the invention aredesired to be protected.

What is claimed is:
 1. An industrial asset tag, comprising: a plastictag body defining a cavity and a pass-through hole, the body beingconstructed of a plastic material and having an outer surface; an RFIDtransceiver in the cavity; and a plug filling substantially all of theportion of the cavity not occupied by the RFID transceiver, such thatthe RFID transceiver is not exposed along the outer surface; whereinwhen the RFID transceiver receives a stimulus signal, it sends an answersignal encoding data associated with a unique identifier.
 2. The tag ofclaim 1, wherein an asset identifier is visibly and legibly placed onthe outside of the tag.
 3. The tag of claim 2, wherein the answer signalalso encodes the asset identifier.
 4. The tag of claim 1, wherein theplug and the body combine to prevent water from reaching the RFIDtransceiver from outside the body.
 5. The tag of claim 1, wherein theplastic material is treated to reduce the natural deterioration of theplastic material.
 6. The tag of claim 1, in combination with an objectpassing through the through-hole, wherein characteristics of the objectare visibly and legibly written on the outer surface of the body.
 7. Thetag of claim 6, wherein: the object is a chain, and the identifier is aserial number associated with the chain.
 8. The tag of claim 1, whereinthe cavity has a rectangular opening; and the portion of the bodyexposed to the cavity is rifled.
 9. A method of manufacturing an assettag, comprising: molding resin having at most about 0.01% moisture in adie to form a tag that has a body and defines a slot that opens to theoutside of the tag body; curing the resin tag to increase its moisturecontent to at least about 2%; placing an RFID transceiver in the slot,wherein when the RFID transceiver receives a stimulus signal, it sendsan answer signal encoding data associated with a unique identifier; andinjecting epoxy in the slot to cover the RFID transceiver.
 10. Themethod of claim 9, further comprising: before the placing step, riflingat least a portion of the surface of the slot.
 11. The method of claim9, wherein the resin is treated to substantially prevent naturaldegradation of the plastic material when exposed to sunlight.
 12. A tagmade according to the method of claim
 9. 13. The method of claim 9,further comprising writing the identifier for the object on the outsideof the tag.
 14. An asset tag, comprising: a first layer offabric-reinforced PVC; a second layer of fabric-reinforced PVC, sealedaround a closed path to the first layer to form an air pocket; an RFIDtransceiver in the pocket, the transceiver being: configured to transmitidentity information in response to a stimulus signal; and protected bythe air pocket from crushing damage.
 15. The asset tag of claim 14,further comprising a lifting device to which the pocket is attached;wherein the identity information identifies the lifting device.
 16. Theasset tag of claim 14, wherein the seal is waterproof.
 17. The asset tagof claim 14, wherein the seal is created by RF welding.
 18. The assettag of claim 14, wherein at least one of the first layer and the secondlayer extends beyond the pocket with a tail of sufficient size to allowattachment of the tail to a device.